The existing metallurgical slag treatment equipment by barrel method is one of currently advanced slag treatment equipments. It has advantages of short flow path, less investment, safety, reliability and low energy consumption, the slag, after having been treated, can be utilized directly, and the pollution is low. The metallurgical slag treatment technology and equipment by barrel method, in particular, a vertical feed double cavity barrel equipment can overcome the inadequacy of traditional slag treatment process and equipments, it has the advantages of short flow path, less investment, convenient operation, low energy consumption and good quality of treated product slag. A prior art patent CN 1141401 C discloses “A Steel Slag Treatment Equipment by Double Cavity Barrel method” for treating steel slag. Please refer to FIG. 1, the equipment has two oppositely open squirrel-cage type barrel bodies consisting of backing rings 16, grid sections 31 and rotary end covers, wherein the grid sections and backing rings are connected together with bolts. Between the open sides of the two barrel bodies there is disposed a flow branching pan 9 capable of synchronously rotating, which divides the two barrel bodies into two relatively independent cavity bodies. The force moment causing the rotation of flow branching pans comes from a mandrel 6. The lower part of flow branching pan is a stationery retaining ring 12 of semi-ring shape having the function of separating the two cavity body and preventing the leakage of slag material 7 and cooling media 8. Below the barrel body is a discharge funnel 13 for discharging pulverized slag. Below the four backing rings are disposed eight sets of supporting roller devices 15 arranged respectively at a certain definite angle supporting the rotating parts of the equipment. A fixed hood 14 having a sealing function is located outside the rotary barrel body. During operation, steel slag is fed into funnel 1, falls onto the flow branching pan 9, and is guided respectively into two barrel bodies, after being cooled and crushed, by cooling body 8 (steel balls) leaks out through the slits between the grid sections, and is discharged out of the equipment through discharge flannel 13. The vapor generated in the process is collected by the fixed hood and discharged through specially provided shell and flue. The equipment uses vertical slag feeding, thus solving the problem of feeding slag of high viscosity relatively perfectly. But its disadvantages are, the barrel is a single layer barrel body construction, thus the cooling of slag material is not sufficient and red slag tends to appear; there are relatively too many supporting devices and the equipment is heavy; its lower space is limited, thus maintenance and repair are inconvenient.
In addition, in the existing double cavity type metallurgical slag treatment equipment by barrel method, the retaining ring is located at the lower part of the rotating flow branching pan within the barrel body. The retaining ring comprises a base plate and side plates on which there are many concave pits. The base plate and side plates form a V-shaped cell, in which slag material and many steel balls are filled. Through the base plate there is drilled a discharge hole. Although such a construction protects the retaining rings the resistance during rotation of barrel body is large and further affects the operation of barrel body and the service life of the retaining ring.
Further as is shown in FIGS. 8 and 9, the existing metallurgical slag treatment equipment by barrel method uses a barrel body in the shape of a circular table, its cone portion is outside an inner barrel body and on its cylindrical portion there are many sending plates uniformly distributed peripherally. The sending plates have an inclination angle α with respect to the radial direction. The slag material after being treated in the inner barrel body falls by gravity to the inside of the conical surface of the outer barrel body and is guided on the inclined surface of the conical body into the cylindrical barrel portion, and under the action of sending plates is sent into a discharge chute and through it out of the equipment. This barrel body suffers the disadvantages that it must have a conical shape of inclination angle α in order to discharge slag material, the value of a being equal to the rest (repose) angle of slag material, generally 45°. In his way the slag material coming down from the inner barrel body can be sent axially to the lower part of the discharge chute. According to the geometrical relationship of the construction, the diameter of the outer barrel body equals to the diameter of the inner barrel body plus twice the process width of inner barrel body, as a result, the outer diameter of barrel body is very large, the weight is large and investment is high.
In addition, referring to FIGS. 12 and 13, the process of the existing metallurgical slag treatment by barrel method is such, through a slag feed inlet slag material enters the rotating inner barrel body, which is a squirrel-cage shape barrel body formed by many grid sections, at two ends of which are two end covers, under the inertia the slag material is thrown onto the surface of cooling media (steel balls), then penetrates by gravity into the slits between steel balls to be cooled and crushed, discharged through the grid sections at the bottom of inner barrel body into the outer barrel body. Generally, with the rotation of inner barrel body only the balls and slag material on the upper surface layer and those near the inner barrel body (lower surface layer) will move along the trajectories shown by arrows in FIG. 13 under the action of frictional and gravitational forces, the steel balls in the middle kidney-shaped portion are far away from the inner barrel body, and are thus subjected to less frictional force by the surrounding steel balls, the motion region of which is smaller, even stationery and undergoes no normal heat exchange. As the hot slag material penetrates downward, the temperature of steel balls in this region increases rapidly and can not be cooled timely, that is, loses the normal effect of heat transfer. especially when the viscosity of hot slag material is high and thus the ability of slag material to penetrate into the slits between steel balls is weak, a large part of slag material will cover the upper surface of steel balls region of kidney shape and form “slag crust”, where the contact area between slag material and steel balls is small, the steel balls taking part in cooling the slag material are those steel balls at the upper surface layer of balls in the kidney-shaped region, and, therefore, their cooling effect is low, tending to give rise to bursting in the barrel body, and the pulverizing effect is bad, tending to result in the discharge of red slag out of the equipment, not only affecting the service life of subsequent equipments, but also yielding product slag of low performance negating its direct utilization.